<!DOCTYPE html>
<html lang="zh-cn">
<head>
	<meta charset="UTF-8">
	<title>任务4</title>
	<style type="text/css">
	*{
		margin: 0;
		padding: 0;
	}
		
		#mainDiv{
			width: 400px;
			height: 200px;
			background-color: #9E9E9E;
			position: absolute;
			left: 50%;
			top: 50%;
			margin-left: -200px;
			margin-top: -100px;
			overflow: hidden;
		}
		#topLeftDiv{
			width: 100px;
			height: 100px;
			border-radius: 50px 50px 50px 50px;
			background-color: #FFB90F;
			position: absolute;
			left: 50%;
			top: 50%;
			margin-left: -250px;
			margin-top: -150px;
		}
		#bottomRightDiv{
			width: 100px;
			height: 100px;
			border-radius: 50px 50px 50px 50px;
			background-color: #FFB90F;
			position: absolute;
			left: 50%;
			top: 50%;
			margin-left: 150px;
			margin-top: 50px;
		}
	</style>
</head>
<body>
	<div id="mainDiv">
		<div id="topLeftDiv"></div>
		<div id="bottomRightDiv"></div>
	</div>
</body>
</html>